Educational device.



c. P. (airman. EDUCATIONAL DEVICE. APPLICATION FILED .IUNE 8.19M.

Patented Feb. 19, 1918.

2 SHEETS-SHEET I.

c. P. GiFFORD. EDUCATIONAL DEVICE. APPLICATION FILED JUNE 8. I911.

Patented Feb. 19, 1918.

2 SHEETS-SHEET 2.

ran sra'rns rarnn'r option;

CYRUS P. GIFFORD, OF ERIE, PENNSYLVANIA, ASSIGNOR OF TWQ-THIRDS TOWILLIAM A. KARLE, F ERIE, PENNSYLVANIA.

EDUCATIONAL DEVICE.

being had to the accompanying drawings,

and to the letters of reference marked thereon, forming part of thisspecification.

My invention relates to educational devices, the object of which is toteach children addition, subtraction and multiplication.

The features of my invention will appear hereinafter and are illustratedin the accompanying drawings in which Figure 1, is a plan view of aneducational device embodying my invention.

Fig. 2, is a like View with a portion of the top plate broken away.

Fig. 3, is a transverse central section of the same.

In these drawings A (see Fig. 3) indicates the bottom plate, which isprovided with a raised rib a around its perimeter, and a central openinga therethrough. Upon the plate A I place a disk B and upon the ribs a Isecure the upper plate C having a central opening 0 therethrough. Withinthe central opening a in the bottom plate A I place the hub D of athumb-wheel D, said hub D touching the under side of the disk B, and inthe opening 0 in the upper plate I place the hub E of an indicator handE, said hub E and hub D being non-rotatably secured to the disk,preferably by means of screws 6 e, or their equivalent, so that when thethumb-wheel I) or the indicator hand E is moved, the disk B will rotatein unison therewith.

The upper plate Chas printed or engraved upon it a dial F divided into77 radial subdivisions numbered from 1 to 77 inclusive, in consecutiveorder, said numbers appearing in a circle G, and in a circle H there isrinted or engraved thereon numbers from 1 to 77 inclusive, not inconsecutive order, the same being mixed up. There is also printed uponthe upper plate C, within the circle J seven. groups of numbers runningfrom 1 to 12 inclusive, each group being 111- .Specification of LettersPatent.

disk B (see Fig.

Patented Feb. 19, 1918.

Application filed June 8, 1917. Serial No. 173,552.

dicat-ed .by a bracket line I, said bracket being numbered from 2 to 7inclusive; and between the circles of numbers G and II there is printedthe letters of the alphabet,

said letters being numbered by the figures in the circle K.

The upper plate C is provided with an elongated opening L, and with asmall opening M therethrough. The indicator hand E is provided with anopening 6 therethrough, which registers with the circle J so that thenumbers in said circle will be.

visible therethrough; and I also preferably provide said indicator handwith a knob E whereby it may be moved as desired. The 2) has printedthereon three circles of numbers N, O and P, in radial sub-divisions,corresponding with the radial sub-divisions on the dial F of the upperplate C, the numbers in the circle N on the disk B being respectivelythe sums of numbers appearing in the corresponding sub-divi sions in thecircles H and G of the dial F on the upper plate, andthe numbersappearing in the several sub-divisions of the circle 0 on the disk Bbeing the 'diiference between the numbers appearing in the correspondingsub-divisions of the circles H and G of the dial F on the upper plate C.The numbers appearing in the several sub-divisions of the circle P ofthe disk B represent the products of multiplying the numbers in theseveral sub-divisions of the circle J by the numbers of the severalbrackets I.

Upon the disk B between the circles of numbers N and 0 there is printeda series of names or words, which have relation to the letters of the,lphabet and the numbers printed in the circle K, as hereinafter setforth.

In operation, the indicator hand E is turned to point to the numbers 40and 51 on the dial F, which turns the disk B so that the sum anddifference of said numbers, viz: 91 and 11 will appear under the openingL in the dial F, and the product of multiplying the numbers in thecircle G by 5, will appear at the small opening M in the dial F, thus 5times 1 (appearing through the opening 6 in the indicator hand E) is 5,(appearing at the opening M) all as shown by full lines in Figs. 1 and2.

To find the words and names in the disk B the operation is as follows,viz: Take the name David for example: D is numbered it v 1 i bers, sums,difierencesand trarlly prlnted thereon.

in the ci r cle K, A is numbered 1, V is numbered 22, 1 is numbered 9,and D is numbered 4. The sum ,of 4,1, 22, 9 and 4 is 40. 7

Turn the indicator hand to point to- &0 in

the circle G on the dial F and said name .will 1 appear at the opening Lin the dial F. Like-' wise any of the Words on said disk B can be.

found. 7

My device is not'an adding machine, it is simply an'educational device,and the'numproducts are arbi- Having thus shown and described .myinvention so that others can utilize the same, I do not WlSh to belimited to the exactconby Letters-Patent, is; V V

1-. In a deviceof the classdescribed, a. dial having aplurality ofcircles of numbers printed in radial sub-divisions and having anelongated opening therethrough, an indicator hand centrally. pivoted insaid dial adapted to point to desired numbers on said dial, a disk undersaid dial secured to and V rotatable with said indicator hand, and hav-7 ing printed thereon in radial subdivisions the sums and'dlfi'erencesof the several numbers in the corresponding sub-divisions on said dial,said sums and differences being Copiu of this patent may be obtained forfive cents each, by addressing the Commissioner of .Pa tents.

visible through said elongated in said dial, substantially as described.2. In afdevice of the classdescribed,"a dial having a circledivided'into radial subdivi- 'sions, and havinggroups-of numbers in saidcircle'running from 1 to 12inc1usive, said groups being consecutivelynumbered from 2 upward, said dial' having an opening there- ','through,an indicator hand centrally pivoted 1n said dial adapted to'be turned toindicate any number in each of'said severalgroups of numbers, adiskunder said dial lnon-arotatably secured to said indicator hand, andhaving printed: thereon figures indicating the product obtained bymultiplying,

the number indicated by the hand by the number of the'gr,oup,said'product appearing at said opening in said dial, described.

3. In a device, of the class described, a V dial having an openingtherethrougln-letters of the alphabet printed onsaid dial, a circle ofnumbers for said letters, another circle of numbers from 1 upward, anindicator hand pivotcd'at the center of said dial, a rotatable diskunder said dialand secured to and rotatable with said hand, Wordsprintedon said disk in radial sub divisions, corresponding With the lastmentioned circle of I numbers substantially as set forth.

In testimony whereof I affix my signature.

crnusr. eIrFoRn, i

Washington, D. C.

substantially as

